D3142: Characterizing the heat tolerance of non-native ambrosia beetles

Ambrosia beetles (Curculionidae: Scolytinae) are among the most destructive and abundant tree pests in the United States. With many non-native ambrosia beetle species arriving inside solid wood packaging material, biosecurity measures are vital for preventing invasions. However, even with International Standards for Phytosanitary Measures No. 15 (ISPM 15), which requires wood packaging materials to be treated with heat or methyl bromide, some species still bypass biosecurity measures and invade. Therefore, we investigated the heat tolerance of two non-native ambrosia beetles (Xylosandrus crassiusculus and Anisandrus maiche) to determine their potential for surviving current ISPM 15 standards (56°C for over 30 minutes). The two species were reared on branches from a common host, red maple (Acer rubrum), and then warmed to randomly determined target temperatures between 40 and 60°C. Survival status was determined upon completion of each bioassay. Our results indicate the temperatures at which heat-driven mortality begins and provide foundational knowledge for determining the temperature × exposure time combinations required to kill these two ambrosia beetle species.